Nainai valves are available in Three bonnet designs. The first design is the Bolted Bonnet, with male-female joint, spiral wound gasket, made in F304L/graphite. Ring joint gasket are also available on request. The second design is the welded bonnet, with a threaded and seal welded joint.On request a full penetration strength welded joint is available. The third design is the pressure seal bonnet, with a threaded and pressure seal bonnet joint. The check valves are also available in three different design configurations. These are piston check, ball check, or swing check designs.
Construction is as follows
※ Full port or conventional port；
※ Lift type check valves；
※ Ball type check valves；
※ Swing type check valves；
※ Acceding to requirement equip inside spring；
※ Bolted bonnet with spiral-wound gasket, threaded and seal welded bonnet or threaded and pressure seal bonnet；
※ Socket weld ends to ASME B16.11；
※ Screwed ends (NPT) to ANSI/ASME B1.20.1；
※ Disc can change for soft seal disc and ball disc.